2. Firm mattresses, firm prices: Shares in Mattress Firm(MFRM) are set to double when trading begins after a major takeover deal was announced.

South Africa's Steinhoff International has agreed to buy the American retailer for $64 per share in cash. The stock closed at $29.75 on Friday.

The equity value of the deal works out to $2.4 billion. Including debt, the offer values Mattress Firm at $3.8 billion.

3. Stocks to watch -- Walmart, Delta, Airbus: Shares in Walmart(WMT) will be in focus Monday after it was reported to be buying the online shopping hub Jet.com for $3 billion. Walmart declined to comment.